What's the crystaline structure? How many sides do the crystals have? They can be worn down, but that piece looks pretty good - count the sides of the one that has the most sides, if that makes sense. Fluorite's crystaline structure is cubicle; if there are more than 4 sides on any of them, it's not fluorite. Beryl (aquamarine, emerald) has six sides, but like I said, some of them could be worn off. I have a hunk of emerald that's about 5 lbs I dug up in Michigan - it's really cool. No, it's not indiginous to that area, the previous owner was a rock hound & evidently when he died his wife dumped/buried his collection & when I started gardening I was finding the coolest rocks I was digging up everything!